List of largest empires

Several empires in human history have been contenders for the largest of all time, depending on definition and mode of measurement.

Of these, area is the most commonly used because it has a fairly precise definition and can be feasibly measured with some degree of accuracy.

[6] The list is not exhaustive owing to a lack of available data for several empires; for this reason and because of the inherent uncertainty in the estimates, no rankings are given.

For context, the land area of the Earth, excluding the continent of Antarctica, is 134,740,000 km2 (52,023,000 sq mi).

For example: in the year 1800, European powers collectively claimed approximately 20% of the Earth's land surface that they did not effectively control.

A map of the British and Mongol empires at their respective greatest extents
The British Empire (red) and Mongol Empire (blue) were the largest and second-largest empires in history, respectively. The precise extent of either empire at its greatest territorial expansion is a matter of debate among scholars.
The home and colonial areas of the world's empires in 1908, as given by The Harmsworth Atlas and Gazetteer
The home and colonial populations of the world's empires in 1908, as given by The Harmsworth Atlas and Gazetteer